CN112727459B - Mining method for reducing mining influence of shallow coal seam - Google Patents
Mining method for reducing mining influence of shallow coal seam Download PDFInfo
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Abstract
The invention relates to a mining method for reducing mining influence of a shallow coal seam, belongs to the technical field of coal seam mining, and solves the problem that in the prior art, after the shallow coal seam is mined, surface buildings and rock stratum structures are damaged. The method comprises the following steps: step 1: predicting the influence range of geological exploration and exploitation; step 2: after the working face is recovered, temporarily supporting the goaf and placing explosives; and step 3: and withdrawing the temporary support, and detonating the explosive to cut the top. The blasting roof cutting processing goaf is arranged after the stoping of the working face is finished, no contradiction exists between the blasting roof cutting processing goaf and the coal mining operation, and the mining progress cannot be influenced; the cut roof has good integrity, the goaf moves up completely, the equivalent burial depth of the coal bed is reduced, the stress concentration of the roadway and the working face is reduced, the roadway is maintained, and rock burst disasters are prevented.
Description
Technical Field
The invention relates to the technical field of coal seam mining, in particular to a mining method for reducing the mining influence of a shallow coal seam.
Background
A lot of successful experiences can be used for reference in the technical field of blasting roof cutting pressure relief in China, and the blasting roof cutting technology is successfully applied to pressure relief in Hara ditch coal mines, Rongtai mines and the like, so that good effects are achieved. For a working face with obvious mine pressure display, as no section protection coal pillar is reserved, when a goaf roof collapses to a limit span, a violent dynamic pressure phenomenon is often accompanied, the roadway roof bears a large pressure, so that the roadway deforms seriously, enterprises have to invest a large amount of energy to maintain the roadway in the goaf with large deformation, but the maintenance effect is unsatisfactory. In order to solve the problem, many mines adopt a roof cutting pressure relief blasting technology to relieve pressure on a working face, so that the stress environment of surrounding rocks of the roadway is effectively improved, and the stress concentration of the surrounding rocks of the roadway is reduced.
When the working face is a non-shallow coal seam, the mine pressure of the working face is mainly influenced by the immediate roof and the basic roof above the working face, and has no obvious relation with the change of the burial depth. When the working face is a shallow coal seam, the mining pressure display degree is greatly influenced by the burial depth, and when the burial depth of the working face is increased, the mining pressure display degree of the working face is more obvious, so that when the shallow coal seam is mined, the mining process is optimized, and the burial depth of the working face is reduced as much as possible.
After coal resources are mined, the damage of a overlying strata structure causes the earth surface to move and deform in different degrees, so that earth surface buildings (structures) are damaged, and the normal production of local enterprises and the normal life of residents are influenced; the damage of the original structure of the rock stratum within the mining influence range can also cause a plurality of problems of water and soil loss, water inrush of a working face and the like.
In summary, in order to reduce the mining influence range as much as possible and improve the mining comprehensive benefit, after the stoping of the working face of the shallow coal seam is finished, the goaf needs to be subjected to blasting and roof cutting treatment.
Disclosure of Invention
In view of the foregoing analysis, the embodiments of the present invention are directed to a mining method for reducing the mining impact of a shallow coal seam, so as to solve the problem of damage to surface buildings and rock strata after mining of the existing shallow coal seam.
The invention provides a mining method for reducing the mining influence of a shallow coal seam, which comprises the following steps:
step 1: forecasting geological exploration and mining influence range;
step 2: after the working face is recovered, temporarily supporting the goaf and placing explosives;
and step 3: and withdrawing the temporary support, and detonating the explosive to cut the top.
Further, in the step 1, the geological exploration includes obtaining the dip angle, the mining height, the burial depth and the roof lithology of the shallow coal seam.
Further, in step 1, surface movement prediction parameters are obtained in the mining influence range prediction, and the surface movement prediction parameters include a subsidence coefficient q, a horizontal movement coefficient b, a main influence tangent tan β, and a mining influence propagation angle θ0Inflection offset S0。
Further, in the step 1, main parameters of an influence area are obtained in the prediction of the mining influence range, and the main parameters of the influence area comprise a main influence radius r, a maximum subsidence value W and an inclined deformation i0Curvature K, horizontal movement U0And horizontal deformation epsilon.
Further, the radius is mainly affected:
maximum sinking value: w ═ mqcos α; oblique deformation:
curvature:
horizontal movement: u shape0bW; horizontal deformation:
wherein H0M is the thickness of the coal bed and alpha is the dip angle of the coal bed.
Further, in the step 1, the limit caving step of the hard top plate of the working face is determined.
Further, the method for calculating the limit caving step of the hard top plate comprises the following steps:
breaking tensile stress of the rock beam:
maximum bending moment of the rock beam:
the loads that the overburden rock layer affects on the hard roof rock beam are as follows:
ultimate caving step of rock beam:
wherein σmaxFor tensile stress of the rock beam, [ sigma ]]For breaking tensile stress of the beam, q is the transmission of the hard beam itself and the overlying strataThe load of the load transfer, H is the thickness of the hard roof rock beam, H1…hnThickness of each overlying rock layer of the rock beam, E elastic modulus of hard roof rock beam, E1…EnThe elastic modulus of each rock stratum covered on the rock beam, gamma is the volume weight of the rock beam with a hard top plate, gamma1…γnThe volume weight of each rock stratum on the rock beam is measured.
Further, the specific steps of step 2 include:
step 2.1: determining blasting charge, arrangement mode of blast holes and blasting influence range according to lithology of the direct roof;
step 2.2: establishing an observation station on the ground surface;
step 2.3: after the working face is recovered, temporary supporting is carried out on the goaf by adopting temporary supporting equipment;
step 2.4: and arranging blasting drill holes in the temporarily-supported goaf, and installing explosives.
Further, in the step 2.1, the blasting parameters include blast hole diameter, blast hole arrangement direction, blast hole row spacing, explosive loading and hole depth.
Furthermore, in step 2.2, the observation stations are arranged on the ground surface right above the goaf, and a group of measuring points are respectively arranged along the trend and the inclination of the working surface.
Further, in the step 2.3, the temporary supporting equipment comprises single hydraulic props, metal hinged top beams, anchor nets and anchor cables.
Further, in the step 3, the length of the suspended ceiling is smaller than the limit caving step of the hard ceiling.
Further, the step 1 specifically comprises the following steps:
step 1.1: carrying out geological survey, drawing a stratum histogram and mastering occurrence conditions of the shallow coal seam;
step 1.2: determining surface movement prediction parameters according to occurrence conditions of coal seams, and predicting mining influence ranges of goafs processed by a caving method and goafs processed by a blasting roof cutting method;
step 1.3: and determining the limit caving step distance of the hard top plate of the working face.
Further, the step 3 specifically comprises the following steps:
step 3.1: after the blasting is ready, withdrawing the temporary supporting equipment;
step 3.2: detonating the explosive to cut the top when the distance of the suspended top reaches the length of the suspended top;
step 3.3: and observing the earth surface influence range.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
(1) the blasting roof cutting processing goaf is arranged after the stoping of the working face is finished, no contradiction exists between the blasting roof cutting processing goaf and the coal mining operation, and the mining progress is not influenced; the cut roof has good integrity, the gob moves upwards completely, the equivalent burial depth of the coal seam is reduced, the stress concentration of the roadway and the working face is reduced, the maintenance of the roadway is facilitated, and the rock burst disaster is prevented; during blasting, the mine pressure is used for cutting off the top plate, so that the explosive consumption can be saved; part of rock mass is exploded in the blasting process, the volume of the fractured rock mass is expanded, and the broken waste rock can fill part of the goaf, so that the goaf can be maintained to be stable;
(2) determining the caving step distance and blasting parameters, simultaneously establishing a ground surface observation station on the ground, carrying out temporary support on the goaf after the working face is mined, arranging blast holes and blasting materials in a temporary support space, and withdrawing temporary support equipment after the blasting preparation work is finished; with the advance of the working face, the suspension distance of the goaf is increased, when the suspension distance reaches the set caving distance, explosive is detonated, and the roof is cut off in sections to fill the goaf; the sequence of filling space and time is adopted without mutual influence; because the completeness of the cut-off top plate is better, the goaf approximately and completely moves upwards, the equivalent burial depth of the coal seam is reduced, the hidden danger of the rock burst of the top plate is eliminated, the problem of the stress concentration of the roadway excavation is solved, the influence range of the surface mining is reduced, and the influence on part of surface buildings is reduced.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.
FIG. 1 is a schematic representation of a formation loading mechanics model of the present invention;
FIG. 2 is a schematic view of the working surface of the present invention advancing from the incision;
FIG. 3 is a schematic illustration of the face of the present invention as it advances from a position spaced from the boundary pillar D;
FIG. 4 is a front view of the present invention as it would be advanced to the gob overhang distance L;
FIG. 5 is a left side view of the inventive face advanced to a gob overhang distance L;
FIG. 6 is a top plan view of the inventive face advanced to the gob overhang distance L;
FIG. 7 is a front elevation view of a goaf roof cut-away after blasting in accordance with the present invention;
figure 8 is a top plan view of the goaf roof cut after blasting in accordance with the present invention.
Reference numerals:
1-a loose layer; 2-a basic roof; 3-direct roof; 4-corner coal pillar; 5-blast hole; 6-suspended ceiling gob; 7-anchor nets and anchor cables; 8-single hydraulic prop; 9-metal hinged top beams; 10-a hydraulic prop; 11-a coal mining machine; 12-a working face to be mined; 13-the track is crosscut; 14-temporary supporting the gob; 15-transporting crossheading; 16-a recovery area; 17-upper goaf after roof caving; 18-roof gangue; 19-ground observation station.
Detailed Description
The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention and not to limit its scope.
In the description of the embodiments of the present invention, it should be noted that the term "connected" is to be understood broadly, and may be, for example, fixed, detachable, or integrally connected, and may be mechanically or electrically connected, and may be directly or indirectly connected through an intermediate medium, unless otherwise specifically stated or limited. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The terms "top," "bottom," "above … …," "below," and "on … …" as used throughout the description are relative positions with respect to components of the device, such as the relative positions of the top and bottom substrates inside the device. It will be appreciated that the devices are multifunctional, regardless of their orientation in space.
Example 1
One embodiment of the present invention, as shown in fig. 1-8, discloses a mining method for reducing the mining impact of a shallow coal seam, comprising the steps of:
step 1: forecasting geological exploration and mining influence range;
step 2: after the working face is recovered, temporarily supporting the goaf and placing explosives;
and step 3: and withdrawing the temporary support, and detonating the explosive to cut the top.
Compared with the prior art, the mining method for reducing the mining influence of the shallow coal seam, which is provided by the embodiment, has the advantages that the blasting roof cutting processing goaf is arranged after the stoping of the working face is finished, no contradiction exists between the blasting roof cutting processing goaf and the coal mining operation, and the mining progress cannot be influenced; the cut roof has good integrity, the goaf moves upwards approximately and completely, the equivalent burial depth of the coal seam is reduced, the stress concentration of the roadway and the working face is reduced, the maintenance of the roadway is facilitated, and the rock burst disaster is prevented; during blasting, the mine pressure is used for cutting off the top plate, so that the explosive consumption can be saved; part of rock mass is exploded in the blasting process, the rock mass is cracked and then expands in volume, and the broken waste rock can fill part of the goaf, so that the goaf can be maintained to be stable.
Step 1: predicting the influence range of geological exploration and exploitation; the method specifically comprises the following steps:
step 1.1: and performing geological survey, drawing a stratum histogram and mastering occurrence conditions of the shallow coal seam. The dip angle, mining height, burial depth and roof lithology of the coal seam need to be mastered in the shallow coal seam.
Step 1.2: and determining surface movement prediction parameters according to occurrence conditions of coal seams, and predicting mining influence ranges of the goaf processed by a caving method and the goaf processed by a blasting roof cutting method.
The surface movement prediction parameters comprise a subsidence coefficient q, a horizontal movement coefficient b, a main influence tangent tan beta and a mining influence propagation angle theta0Inflection offset S0。
The main parameters of the influence area include: mainly affecting the radius r, the maximum sag value W, the inclination deformation i0Curvature K, horizontal movement U0And horizontal deformation epsilon.
The main influence radius is:
maximum sinking value: w ═ mqcos α;
oblique deformation:
curvature:
horizontal movement: u shape0＝bW；
Horizontal deformation:
wherein H0Is the average depth of burial in meters, m is the thickness of the coal seam in meters, and alpha is the dip angle of the coal seam in degrees.
Step 1.3: and determining the limit caving step distance of the hard top plate of the working face.
Hard roof limit collapse step L0And simplifying the stope into a rock stratum load mechanics model for calculating the fracture limit span of the hard roof, wherein the model is as shown in figure 1, and the rock beam is in tensionThe top plate is cracked when the force is larger than the breaking tensile stress of the rock beam.
Breaking tensile stress of the rock beam:
maximum bending moment of the rock beam:
the loads that consider the effect of the overburden rock on the hard roof rock beam are:
ultimate caving step of rock beam:
wherein σmaxFor tensile stress of the rock beam, [ sigma ]]For breaking tensile stress of the rock beam, q is the load transferred by the hard rock beam and the overlying rock stratum, H is the thickness of the hard roof rock beam, and H is1…hnThickness of each rock layer overlying the rock beam, E elastic modulus of hard roof rock beam, E1…EnThe elastic modulus of each rock stratum covered on the rock beam, gamma is the volume weight of the rock beam with a hard top plate, gamma1…γnThe volume weight of each rock stratum on the rock beam is measured.
And 2, step: after the working face is recovered, temporarily supporting the goaf and placing explosives; the method comprises the following specific steps:
step 2.1: and determining the blasting charge amount, the arrangement mode of blast holes and the blasting influence range according to the lithology of the direct roof.
The main parameters of blasting include the diameter of blast holes, the arrangement direction of the blast holes, the row spacing of the blast holes, the loading amount and the depth of the holes.
Step 2.2: and (4) establishing an observation station on the ground surface. The observation stations are arranged on the earth surface right above the goaf, and a group of measuring points are respectively arranged along the trend and the inclination of the working surface to observe the subsidence of the earth surface.
Step 2.3: and after the working face is recovered, temporary supporting is carried out on the goaf by adopting temporary supporting equipment. The temporary support equipment comprises single hydraulic prop, metal hinged top beam, anchor net and anchor cable.
Step 2.4: and arranging blasting drill holes in the temporarily-supported goaf, and installing explosives.
And step 3: withdrawing the temporary support, and detonating the explosive to cut the top; the method comprises the following specific steps:
step 3.1: and after the blasting is ready, withdrawing the temporary support equipment.
Step 3.2: and detonating the explosive to cut the top when the distance of the suspended top reaches the length of the suspended top. The length L of the suspended ceiling should be less than the limit caving step L0。
Step 3.3: and observing the earth surface influence range.
In this embodiment, the blasting process is: arranging blasting drill holes in the temporary supporting goaf, arranging explosives, detonators, lead wires and the like in the blasting drill holes, plugging the blasting drill holes by using stemming, withdrawing the temporary supporting equipment after blasting preparation is finished, and blasting when the suspended area reaches a set step distance.
According to the mining method for reducing the mining influence of the shallow coal seam, the caving step distance and the blasting parameters are determined according to the occurrence characteristics of the shallow coal seam, meanwhile, a surface observation station is arranged on the ground, a goaf is temporarily supported after the mining of a working face is finished, blast holes and blasting materials are arranged in a temporary supporting space, and the temporary supporting equipment is withdrawn after the blasting preparation work is finished; with the advance of the working face, the suspension distance of the goaf is increased, when the suspension distance reaches the set caving distance, explosive is detonated, and the roof is cut off in sections to fill the goaf; the sequence of filling space and time is adopted without mutual influence; because the completeness of the cut-off top plate is better, the goaf approximately and completely moves upwards, the equivalent burial depth of the coal seam is reduced, the hidden danger of the rock burst of the top plate is eliminated, the problem of the stress concentration of the roadway excavation is solved, the influence range of the surface mining is reduced, and the influence on part of surface buildings is reduced.
Example 2
In another embodiment of the invention, a mining method for reducing the mining influence of a shallow coal seam is disclosed, and the method for reducing the mining influence of the shallow coal seam in the embodiment 1 is adopted.
Taking a certain working face of a coal seam in a Shendong mining area 1-2 as an example, as shown in the figure 1-2, the working face has the trend of 4200m in length, the trend of 120m in length, the coal seam inclination angle of 3 degrees, the mining height of 5m and the average burial depth of 130m, the direct roof 3 is sandstone with the thickness of 0-15 m, the basic roof 2 is sandstone with the thickness of 6-15 m; the direct bottom plate is mudstone, the thickness of the direct bottom plate is 2-3 m, and the base bottom is sandstone. A basic roof 2 is arranged above the direct roof 3, a unconsolidated layer 1 is arranged above the basic roof 2, a surface observation station 19 is arranged above the unconsolidated layer 1, and specific parameters of partial rock formation properties are shown in a table 1.
TABLE 1 table of formation physicomechanical property parameters
The estimated parameters of the mining influence range of the goaf processed by adopting the caving method and the goaf processed by adopting the blasting roof cutting method are shown in a table 2. The statistical results of the predicted results of the influence ranges such as mining influence radius, maximum subsidence value and the like calculated according to the formula in example 1 are shown in table 3.
TABLE 2 mining impact Range prediction parameters Table
As can be seen from table 3, the radius of influence of mining by the blasting roof cutting method is reduced by about 3.3m compared with that by the caving method, the expected results of the maximum subsidence value and the horizontal movement are substantially the same, the curvature, the horizontal deformation and the inclined deformation value are slightly increased, but the amplification is smaller, according to the mining damage protection principle, when any value of i ═ 3mm/m, epsilon ═ 2mm/m or K ═ 0.2mm appears at the outermost boundary, the boundary is determined to be a moving critical boundary, and after the goaf is processed by the blasting roof cutting method, the moving critical boundary is reduced by 2.22m towards the center of the moving basin, so that the range of influence of mining by the blasting roof cutting method can be effectively reduced.
TABLE 3 statistical table of estimated mining impact range
The ultimate span L of the initial roof caving of the hard rock beam is calculated by substituting the parameters in Table 1 into the formula in example 10The process is as follows:
q0＝γH＝23.52×4.12＝96.9kN·m-2；
wherein q is0For loading the hard rock beam with the first layer covering, the unit is kN.m-2(ii) a Gamma is the volume weight of the overlying first stratum and has the unit of kN/m3(ii) a H is the thickness of the overlying first layer of rock beam and has the unit of m.
Considering the effect of the overlying second layer on the hard rock beam
Wherein (q)1)0Loading the hard rock beam with a second overlying layer in kN m-2(ii) a Gamma is the volume weight of the overlying first stratum and has the unit of kN/m3；γ1The unit of the volume weight of the overlying second rock layer is kN/m3(ii) a H is the thickness of the overlying first layer of rock beam, and the unit is m; h is1The thickness of the overlying second layer of rock beam is m; e is the elastic modulus of the overlying first layer of the rock beam, and the unit is MPa; e is the elastic modulus of the overlying second layer of the rock beam and has the unit of MPa.
Due to (q)1)0＜q0Then q is0As a load on the hard rock beam.
From table 1, the thickness H of the hard roof slab is 4.12m, [ σ ] is found]＝1.5MPa，q＝96.9kN·m-2And substituting the data into the limit caving step of the available coal seam roof of the example 1:
wherein L is0Is the limit caving step, unit m; q isThe first overlying layer is loaded on the hard rock beam in kN.m-2(ii) a H is the thickness of the hard roof rock beam and the unit is m; [ sigma ] A]Ultimate tensile strength in MPa.
The length L of the periodic roof-caving suspended roof of the hard roof is less than L0And considering safety factors, determining that the top plate is set to be in a suspension distance of 15m, and blasting and jacking.
Before the mining of the working face, an observation station 19 is established on the earth surface right above the working face, two mutually perpendicular measuring lines are respectively arranged along the trend and the inclination of the working face, and the distance between the measuring points is 10-15 m.
As shown in fig. 3-7, a coal mining machine 11 is driven from the corner coal pillar 4 to form a cut hole, a stoping roadway system is formed by a track crossheading 13 and a transportation crossheading 15, the coal mining machine is driven to a working face 12 to be mined by adopting backward mining to recover coal resources in an area shown by a stoping area 16, and a stope is supported by a hydraulic support 10. After stoping is finished, the suspended ceiling gob 6 is supported by a single hydraulic prop 8 and a metal hinged top beam 9 in time in cooperation with an anchor net and an anchor cable 7, after supporting is finished, the positions of the blastholes 5 are arranged according to the position shown in the figure 5, the diameter of each blasthole 5 is 30-50 mm, the arrangement direction deviates to the gob side by 10-20 degrees along the vertical direction, the row spacing between the blastholes 5 is 4-8 m, the loading is 10-15 kg/hole, and the hole depth is 8-13 m. After the blast holes 5 are arranged, the explosives, the detonators, the leads and the like are arranged in the blasting drill holes and are plugged by stemming.
And after the blasting preparation work is finished, withdrawing the single hydraulic prop 8, the metal hinged top beam 9, the anchor net and the anchor cable 7, and waiting for blasting in the suspended ceiling gob 6.
As shown in fig. 3, when the distance of the suspended roof gob 6 reaches 15m (L is 15m), after the side end of the articulated cap gob is 5m away from the nearest blast hole 5 (S is 5m), blasting and caving are implemented, a millisecond delay detonator is selected for initiation, and the expected caving effect is shown in fig. 7-8. At the moment, the upper goaf 17 is in an empty state after roof caving, roof gangue 18 is regularly put to the suspended roof goaf 6, and the surrounding rock of the temporary support goaf 14 after roof caving possibly generates dynamic load influence and support is reinforced.
After the first caving is carried out, the caving is carried out along with the advance of the working face, and the caving is carried out in sequence according to the method, so that the goaf caving treatment of the working face is completed, in order to research the ground surface moving deformation condition caused by the stoping of the filling working face, the ground surface buildings are protected, and the ground surface influence range is observed after the goaf is stable. After the earth surface influence range is observed, the sinking basin can be found along the direction of the survey line or at a certain angle with the survey line, the influence rule of various factors on the basin can be determined by analyzing the monitoring data, and the reason of the influence rule can be analyzed. Because the subsidence basins of the ground surface can present different rules under the influence of different factors, the collected data are comprehensively analyzed, the influence rule of various factors on the movement deformation of the ground surface is determined, the basin deformation reason is explored, and the caving process is optimized, so that the basis is provided for the design of 'three lower' coal pressing filling mining and the like, the ground influence caused by mining is reduced, the mining rate of mine resources is improved, and the service life of a mine is prolonged.
According to the theory of predicting the surface movement deformation by the probability integration method, the comprehensive analysis of the result obtained by combining the actual mining conditions of the coal seams of the Shendong mining area 1-2 in the embodiment 2 can be known as follows: the mining influence radius of the mining sample working face by adopting a caving method is 86.67 m; the mining influence radius by adopting the blasting roof cutting method described by the invention is 83.33m, and is reduced by about 3.3m compared with the caving method; after the goaf is treated by the blasting roof cutting method, the earth surface is inclined and deformed i0The height of the blasting roof cutting method is reduced by 0.7mm/m, the horizontal deformation epsilon is reduced by 0.26mm/m, and the moving critical boundary is reduced by 2.22m towards the center of the moving basin, so that the blasting roof cutting method is considered to be capable of effectively reducing the mining influence range.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (1)
1. A mining method for reducing mining influence of a shallow coal seam is characterized by comprising the following steps:
step 1: predicting the influence range of geological exploration and exploitation;
the step 1 specifically comprises the following steps:
step 1.1: carrying out geological survey, drawing a stratum histogram and mastering occurrence conditions of the shallow coal seam;
step 1.2: determining surface movement prediction parameters according to occurrence conditions of coal seams, and predicting mining influence ranges of goafs processed by a caving method and goafs processed by a blasting roof cutting method;
step 1.3: determining the limit caving step distance of a hard top plate of a working face;
step 2: after the working face is recovered, temporarily supporting the goaf and placing explosives;
the specific steps of the step 2 comprise:
step 2.1: determining blasting parameters and blasting influence range according to lithology of the direct roof; the arrangement direction of blast holes deviates to the side of a mining area by 10-20 degrees along the vertical direction;
step 2.2: establishing an observation station on the ground surface;
step 2.3: after stoping of the working face, temporarily supporting the goaf by using temporary supporting equipment;
in the step 2.3, the temporary support equipment comprises single hydraulic props, metal hinged top beams, anchor nets and anchor cables;
step 2.4: arranging blasting drill holes in the temporarily-supported goaf, and installing explosives;
and 3, step 3: withdrawing the temporary support, and detonating the explosive to cut the top;
the step 3 specifically comprises the following steps:
step 3.1: after the blasting is ready, withdrawing the temporary supporting equipment;
step 3.2: detonating the explosive to cut the top when the distance of the suspended top reaches the length of the suspended top; when a temporary supporting gob is arranged on the side of a working face to be mined of the suspended roof gob, the suspended roof distance reaches L, and the side end of the gob of the hinged top beam leaves the nearest blasthole S, blasting and caving are carried out;
step 3.3: observing the earth surface influence range;
in the step 1, geological exploration comprises the steps of obtaining the dip angle, the mining height, the burial depth and the roof lithology of the shallow coal seam;
in the step 1, earth surface movement prediction parameters are obtained in the prediction of the mining influence range, and the earth surface movement prediction is carried outThe parameters including the coefficient of settlingqCoefficient of horizontal movementbMain influence tangenttanβAngle of propagation of mining effectsθ 0 Inflection offsetS 0 ；
In the step 1, main parameters of the influence area are obtained in the prediction of the mining influence range, and the main parameters of the influence area comprise main influence radiusrMaximum sinking valueWAnd inclined deformation ofі 0 Curvature of the surfaceKHorizontally moveU 0 And horizontal deformationɛ；
In the step 2.1, the blasting parameters comprise blast hole diameter, blast hole arrangement direction, blast hole row spacing, explosive loading and hole depth;
in the step 2.2, the observation stations are arranged on the earth surface right above the goaf, and a group of measuring points are respectively arranged along the trend and the inclination of the working surface.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101705821A (en) * | 2009-10-29 | 2010-05-12 | 太原理工大学 | Method for controlling roof caving under condition of hardroof in coal mining |
| CN102758622A (en) * | 2012-04-28 | 2012-10-31 | 中国神华能源股份有限公司 | Monitoring method for earth surface environment damage in underground mining area |
| CN104453899A (en) * | 2014-11-06 | 2015-03-25 | 大同煤矿集团有限责任公司 | Safety recovery method of island working surface under complicated condition |
| CN105257293A (en) * | 2015-09-24 | 2016-01-20 | 中国矿业大学 | Method for mining pressed coal below shallow buried gas delivery pipelines |
| CN108457651A (en) * | 2018-01-24 | 2018-08-28 | 河南理工大学 | A kind of coal mine roadside packing gob side entry retaining hydraulic splitting cuts top method |
| CN110080769A (en) * | 2019-05-09 | 2019-08-02 | 大同煤矿集团有限责任公司 | A kind of coal mine faces sky stope drift active workings tight roof ground and precisely cuts top pressure relief method |
| CN111022050A (en) * | 2019-12-16 | 2020-04-17 | 山东省邱集煤矿有限公司 | Fully-closed blasting pressure relief and self-retained roadway method for grouting reconstruction of composite roof |
-
2020
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-
2021
- 2021-11-26 ZA ZA2021/09624A patent/ZA202109624B/en unknown
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101705821A (en) * | 2009-10-29 | 2010-05-12 | 太原理工大学 | Method for controlling roof caving under condition of hardroof in coal mining |
| CN102758622A (en) * | 2012-04-28 | 2012-10-31 | 中国神华能源股份有限公司 | Monitoring method for earth surface environment damage in underground mining area |
| CN104453899A (en) * | 2014-11-06 | 2015-03-25 | 大同煤矿集团有限责任公司 | Safety recovery method of island working surface under complicated condition |
| CN105257293A (en) * | 2015-09-24 | 2016-01-20 | 中国矿业大学 | Method for mining pressed coal below shallow buried gas delivery pipelines |
| CN108457651A (en) * | 2018-01-24 | 2018-08-28 | 河南理工大学 | A kind of coal mine roadside packing gob side entry retaining hydraulic splitting cuts top method |
| CN110080769A (en) * | 2019-05-09 | 2019-08-02 | 大同煤矿集团有限责任公司 | A kind of coal mine faces sky stope drift active workings tight roof ground and precisely cuts top pressure relief method |
| CN111022050A (en) * | 2019-12-16 | 2020-04-17 | 山东省邱集煤矿有限公司 | Fully-closed blasting pressure relief and self-retained roadway method for grouting reconstruction of composite roof |
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